1. Field of the Invention
The invention relates to a flat panel display device, and more particularly, to an organic electro-luminescence display device and a method for fabricating the same. Although embodiments of the invention is suitable for a wide scope of applications, it is particularly suitable for increasing production yield in fabricating an organic electro-luminescence device and for improving light efficiency in an organic electro-luminescence display device.
2. Discussion of the Related Art
An electro-luminescence display device generates light based on the principle of electroluminescence. An exciton, which consists of an excited electron-hole pair, is generated inside an emissive layer, and when the exciton's electron and hole combine, a photon can be emitted. Thus, an organic electro-luminescence display device is a self-emission type display device unlike a liquid crystal display (LCD) device, since it does not require an external backlight unit for illuminating light. Therefore, an organic electro-luminescence display device has advantages of light weight, a slim profile, low voltage driving, a high light-emission efficiency, a wide viewing angle, and a fast response time. An organic electro-luminescence display device also is advantageous in realizing a high quality moving image.
In addition, an organic electro-luminescence display device is mostly fabricated using deposition and encapsulation processes, and has a simpler fabrication process in comparison to LCDs and plasma display panels (PDPs). Also, when the organic electro-luminescence display device is an active matrix type using a thin film transistor (TFT) as a switching device in each pixel, high brightness is obtained using a low current. Thus, an organic electro-luminescence display device has further advantages of low power consumption, high definition, and a large size.
FIG. 1 is a cross-sectional schematic diagram illustrating an organic electro-luminescence display device according to the related art. In FIG. 1, an active-matrix type organic electro-luminescence display device includes a substrate 10 having thin film transistors (TFTs) Tr provided thereon. Each of the TFTs Tr includes a gate electrode 15, an active layer 25, and source/drain electrodes 27a and 27b. An array device is defined by the TFTs Tr. A passivation layer 20 is formed on the TFTs Tr, and a first electrode 30 is formed on a portion of the passivation layer 20 and electrically connected to the drain electrode 27b. 
An organic light-emitting layer 50 and a second electrode 60 are formed on the first electrode 30. The second electrode 60 can be used as a common electrode, and can be formed over the entire surface of the substrate 10. An insulating layer 40 is formed between the second electrode 60 and the passivation layer 20. Light can be emitted from the organic light-emitting layer 50 by a voltage between the first electrode 30 and the second electrode 60. An organic light-emitting diode (OLED) E is defined by the first electrode 30, the organic light-emitting layer 50, and the second electrode 60.
In addition, a sealant 70 is formed on an outer region of the substrate 10 to protect the OLED E from external moisture and oxygen, and then an encapsulation process of attaching the substrate 10 to an encapsulation substrate 80 is performed, so that the organic electro-luminescence display device is fabricated. Since the organic electro-luminescence display device is formed by attaching the substrate 10 including the array device and the OLED, to the encapsulating substrate 80, he yield of the array device and the yield of the OLED determine a yield of the organic electro-luminance display device. Thus, the yield of an entire process is considerably limited by a manufacturing process of the OLED. For example, even when the array device is properly formed, the organic electro-luminance display device is considered as a defective device when a defect is generated by foreign substances or other factors while an organic light-emitting layer using a thin film of about 1000 Å is formed.
Accordingly, a loss in the related costs and material costs consumed for manufacturing a good array device is generated, to thereby reduce product yield. In addition, although the related art organic electro-luminance display device has stability by an encapsulation process and a high degree of freedom in a process, there exists a limitation in an aperture. Therefore, it is difficult to fabricate the related art organic electro-luminance display device as a high resolution display device.